Rosana Augusto of Brazil and Australia's Lisa De Vanna in action during their teams' international on Sunday. Photograph: Chris Hyde/Getty Images

The Football Federation Australia chief executive, David Gallop, says he's looking into allegations of a revolt by the Matildas players against coach Hesterine de Reus.

Gallop was at the Queensland Sports and Athletics Centre in Brisbane on Sunday to watch the Australian women's side go down 1-0 to Brazil in the first of two tune-up matches against the South Americans ahead of the Matildas' Asian Cup title defence in May.

That result played second fiddle to revelations that Australian players have allegedly approached Professional Footballers Australia (PFA) union to take action against De Reus over her tough disciplinarian line.

Gallop said the governing body was working quickly to investigate the "concerning reports". He confirmed that national technical director Han Berger, head of national performance Luke Casserly – who has been with the team this week – and former Matilda and current women's football co-ordinator Sarah Walsh would put together a report.

"We will put a report together as quickly as possible," he said. "We'll work out how to take it forward from there. At the moment we are getting on top of these concerning reports. We'll make sure we do a thorough job on that first."

Some of the reported complaints have included being in virtual lockdown at team hotels, being barred from seeing parents and general disenchantment with de Reus's hardline coaching methods.

Ellyse Perry, the highest-profile player in the squad, has also been shown the door by the coach who doesn't believe the 23-year-old can become a world-class footballer as long as she is playing cricket for Australia.

De Reus took her place beside the players' bench on Sunday, but it remains a distraction ahead of an Asian Cup campaign where the Matildas need a top-five finish to secure a World Cup berth.

If the talk of mutiny against the coach was true leading into the match, it didn't affect the Matildas on the field as they banged bodies and took the game to the world No6 side.

Debora "Debinha" Oliveira broke the deadlock in the 67th minute with a well-constructed play that put her one-on-one with Matildas goalkeeper Brianna Davey, who had saved several previous chances but was powerless to stop the Brazilian striker in clear space.

Striker Michelle Heyman had a chance to level the scores in injury time but her shot sailed just wide.